Page 152 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-152
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991958: diagnostic tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
MB991813: SWS Monitor Kit
MB991806: SWS Monitor Cartridge
MB991812: SWS Monitor Harness (For Column-ECU)
MB991822: Test Probe Harness
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the ETACS-ECU.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958. Connect special tool MB991910 before con-
necting special tool MB991812. Be sure to connect special
tool MB991806 after turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) Turn the ignition switch to the "ON" position.
(3) Operate the diagnostic tool MB991958 according to the
procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
(4) diagnostic tool MB991958 should show "OK" on the "ECU
COMM Check" menu for the "ETACS ECU" menu.
Q: Is "OK" displayed for the "ETACS ECU" menu?
YES : Go to Step 2.
NO : Refer to Inspection Procedure A-3 "Communication
with the ETACS-ECU is not possible P.54B-74."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-153
STEP 2. Check the input signal by using "DATA LIST"
menu of the SWS monitor.
Turn the ignition switch to the "ON" position before checking
input signals from the ignition switch (IG1).
(1) Operate the diagnostic tool MB991958 according to the
procedure below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "ETACS ECU."
(2) Check that normal conditions are displayed for the items
described in the table below.
Q: Does the diagnostic tool MB991958 display "IG SW
(IG1)" as normal condition?
YES : Go to Step 3.
NO : Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive any signal from the ignition switch
(IG1) P.54B-408."
STEP 3. Check power window relay connector C-203 for
loose, corroded or damaged terminals, or terminals
pushed back in the connector.
Q: Is power window relay connector C-203 in good
condition?
YES : Go to Step 4.
NO : Repair or replace the damaged component(s). Refer
to GROUP 00E, Harness Connector Inspection
P.00E-2. The power windows function should now
work normally. ITEM NO. ITEM NAME NORMAL CONDITION
ITEM 30 IG SW (IG1) ON
Page 161 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-161
INSPECTION PROCEDURE D-2: Power Window: The power window timer function does not work
normally.
NOTE: This troubleshooting procedure requires use
of diagnostic tool MB991958 and SWS monitor kit
MB991813. For details on how to use the SWS mon-
itor, refer to "How to connect SWS monitor
P.54B-13."
.
CIRCUIT OPERATION
The ETACS-ECU operates the power window timer
function according to the following signals:
Ignition switch (IG1)
Front door switch
.
TECHNICAL DESCRIPTION (COMMENT)
If the power window timer function does not work
normally, its input circuit, the ETACS-ECU or the
front-ECU may be defective.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The wiring harness or connectors may have
loose, corroded, or damaged terminals, or termi-
nals pushed back in the connector
The ETACS-ECU may be defective
Page 162 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-162
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991958: diagnostic tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
MB991813: SWS Monitor Kit
MB991806: SWS Monitor Cartridge
MB991812: SWS Monitor Harness (For Column-ECU)
MB991822: Test Probe Harness
STEP 1. Use diagnostic tool MB991958 to select "ECU
COMM Check" on the SWS monitor display.
Check the ETACS-ECU.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958. Connect special tool MB991910 before con-
necting special tool MB991812. Be sure to connect special
tool MB991806 after turning on special tool MB991824.
(1) Connect the special tool. Refer to "How to connect SWS
monitor P.54B-13."
(2) Turn the ignition switch to the "ON" position.
(3) Operate the diagnostic tool MB991958 according to the
procedure below to display "ECU COMM Check."
a. Select "Interactive Diagnosis."
b. Select "System Select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "ECU COMM Check."
(4) diagnostic tool MB991958 should show "OK" on the "ECU
COMM Check" menu for the "ETACS ECU" menu.
Q: Is "OK" displayed for the "ETACS ECU" menu?
YES : Go to Step 2.
NO : Refer to Inspection Procedure A-3 "Communication
with the ETACS-ECU is not possible P.54B-74."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-163
STEP 2. Check the input signal by using "DATA LIST"
menu of the SWS monitor.
Turn the ignition switch to the "ON" position before checking
input signals from the ignition switch (IG1).
(1) Operate diagnostic tool MB991958 according to the
procedure below to display "ETACS ECU."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "SWS MONITOR."
e. Select "Data List."
f. Select "ETACS ECU."
(2) Check that normal conditions are displayed for the items
described in the table below.
Q: Does the diagnostic tool MB991958 display the items
"IG SW (IG1)", "FRONT DOOR SW" as normal
condition?
Normal condition displayed for all the items : Replace
the ETACS-ECU. Verify that the power window timer
works normally.
Normal condition is not displayed for "IG SW (IG1)" :
Refer to Inspection Procedure M-2 "ETACS-ECU
does not receive any signal from the ignition switch
(IG1) P.54B-408."
Normal condition is not displayed for "FRONT DOOR
SW" : Refer to Inspection Procedure M-4 "ETACS-ECU
does not receive any signal from the front door
switches P.54B-413." ITEM NO. ITEM NAME NORMAL CONDITION
ITEM 30 IG SW (IG1) OFF
ITEM 32 FRONT DOOR SW
Page 191 of 1500
SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-191
INSPECTION PROCEDURE E-1: Keyless Entry System: Keyless entry system does not operate.
.
CIRCUIT OPERATION
A receiver is incorporated in the ETACS-ECU. This
receiver receives a lock or unlock signal from the
transmitter.
.
TROUBLESHOOTING HINTS
Refer to circuit diagrams GROUP-90
Refer to configuration diagrams GROUP-80
The RKE transmitter may be defective
The ETACS-ECU may be defective
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991958: diagnostic tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Verify the central door locking system.
Q: Does the central door locking system work normally?
YES : Go to Step 2.
NO : Refer to Inspection Procedure C-1 "The central door
locking system does not work at all P.54B-122."
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SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-192
STEP 2. Check the input signal (by using the pulse check
mode of the monitor).
Check input signals from the transmitter.
To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect diagnostic tool MB991958.Refer to "How to
connect SWS monitor P.54B-13."
(2) Operate diagnostic tool MB991958 according to the
procedure below to display "Pulse check."
a. Select "Interactive Diagnosis."
b. Select "System select."
c. Select "SWS."
d. Select "Pulse Checking."
(3) Push the transmitter "LOCK" or "UNLOCK" button.
(4) Check that diagnostic tool MB991958 sounds
Q: When the transmitter "LOCK" or "UNLOCK" button is
turned ON, does diagnostic tool MB991958 sound?
YES : Replace the ETACS-ECU. All the doors can be locked
or unlocked by means of the transmitter.
NO : Refer to Inspection Procedure N-8 "ETACS-ECU
does not receive any signal from the lock, unlock,
trunk or panic switch P.54B-472."
Page 194 of 1500

SYMPTOM PROCEDURES
SIMPLIFIED WIRING SYSTEM (SWS)54B-194
DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991958: diagnostic tool (MUT-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: MUT-III USB Cable
MB991910: MUT-III Main Harness A
STEP 1. Verify the keyless entry system.
Q: Does the keyless entry system work normally?
YES : Go to Step 2.
NO : Refer to Inspection Procedure E-1 "Keyless entry
system does not operate P.54B-191."
STEP 2. Check the configuration function.
Q: Has the answerback function been enabled by means of
the adjustment function?
YES : Go to Step 3.
NO : Enable the answerback function by means of the
adjustment function. Verify that the answerback
functions work normally.
STEP 3. Verify trouble symptom.
Q: Which answerback function is defective?
Only the dome lamp : Go to Step 4.
Only the turn-signal lamps : Go to Step 5.
Only the horn : Go to Step 6.
Dome lamp, turn-signal lamps and horn : Replace the
ETACS-ECU. Verify that the answerback functions
work normally.
STEP 4. Verify the dome lamp.
Q: Does the dome lamp illuminate normally?
YES : Replace the ETACS-ECU. Verify that the answerback
functions work normally.
NO : Refer to Inspection Procedure K-1 "The dome lamp
do not illuminate and go out normally P.54B-359."
STEP 5. Verify the hazard warning lamp.
Q: Does the hazard warning lamp work normally?
YES : Replace the ETACS-ECU. Verify that the answerback
functions work normally.
NO : Refer to Inspection Procedure I-2 "Hazard warning
lamps do not flash when the hazard warning lamp
switch is turned on P.54B-314."